Abstract
Improving feed efficiency is important for decreasing feed cost in poultry production, because feed account for approximately 70% of the total production costs. The selection of feed efficiency may affect other important economic traits. Therefore, the objectives of this present study was to evaluate the relationships of the residual feed intake (RFI) with live body weight, carcass weight, carcass composition, and size of small intestines in a population of F(2) Pekin ducks. Nine-hundred and eighty F(2) ducks were derived from a cross between 40 Pekin ducks and 10 Mallard ducks. The results showed no significant correlation of RFI with live body weight and eviscerated carcass weight. RFI had negative effects on breast meat weight and gizzard weight. A positive correlation of RFI with abdominal fat weight, skin weight, and jejunum length was detected. Our results indicated that the selection of RFI could improve the feed efficiency of ducks without affecting their carcass compositions.